Mario's Face (lost Nintendo DS tech demo; 2004)
Mario's Face was a Nintendo DS tech demo that was developed by Nintendo EAD and shown at E3 2004 to display the capabilities of Nintendo's then new system.
The player could select Mario or Wario and then use the stylus on the touch screen, grab parts of Mario/Wario's faces, and pull and stretch them, similar to the Super Mario 64 title screen and, to a lesser degree, the Mario Party "Face Lift" minigames. This feature was also put into Super Mario 64 DS, albeit in a far simpler form.
This particular demo hasn't been shown since its E3 presentation and has not been dumped online.